Get Programming with JavaScript

Get Programming with JavaScript - Listing 5.11

Listing 5.11 - Displaying a player's location

var showPlayerPlace;

showPlayerPlace = function (playerName, playerPlace) {
    console.log(playerName + " is in " + playerPlace);
};

showPlayerPlace("Kandra", "The Dungeon of Doom");
showPlayerPlace("Dax", "The Old Library");

Further Adventures

Listing 5.11 - Displaying a player's location - Task 1

Inside the console.log parentheses, change playerName to playerName[0]

var showPlayerPlace;

showPlayerPlace = function (playerName, playerPlace) {
    console.log(playerName[0] + " is in " + playerPlace);
};

showPlayerPlace("Kandra", "The Dungeon of Doom");
showPlayerPlace("Dax", "The Old Library");

The playerName variable has been assigned a string, the name of a player.

The square brackets on the end of the variable name allow us to access a single character in the string.

The index in the square brackets is zero-based. That means that an index of zero corresponds to the first character. playerName[0] will give the first letter in the player's name.

Listing 5.11 - Displaying a player's location - Task 2

Change the number in the brackets to 1.

var showPlayerPlace;

showPlayerPlace = function (playerName, playerPlace) {
    console.log(playerName[1] + " is in " + playerPlace);
};

showPlayerPlace("Kandra", "The Dungeon of Doom");
showPlayerPlace("Dax", "The Old Library");

playerName[1] will give the second letter in the player's name. (Remember the index is zero-based.)

Listing 5.11 - Displaying a player's location - Task 3

What happens when you change the number to 3? Why?

var showPlayerPlace;

showPlayerPlace = function (playerName, playerPlace) {
    console.log(playerName[3] + " is in " + playerPlace);
};

showPlayerPlace("Kandra", "The Dungeon of Doom");
showPlayerPlace("Dax", "The Old Library");

playerName[3] will give the fourth letter in the player's name. (Remember the index is zero-based.)

ERROR! - But "Dax" only has three letters. You can't access the fourth letter of a string with only three characters.